Heterogeneity in antisocial behaviours and comorbidity with depressed mood: a behavioural genetic approach

Background: Antisocial behaviour is often comorbid with depressed mood but is itself a collection of heterogeneous behaviours. Using a genetically informative design, we examine heterogeneity in anti- social behaviour and overlaps between different forms of antisocial behaviour with depressed mood. Methods: Data were drawn from the G1219 large-scale community sample containing self-report questionnaire data from 941 twin pairs and 328 sibling-pairs aged 12–21 years. Results: Inter-correlations among oppositionality, physical aggression and delinquency, and between the antisocial subscales and depressed mood, were mediated by genetic and non-shared environmental influences. Genetic factors generally contributed more to the correlations than the non- shared environment. Conclusions: These results indicate that many genetic and non-shared envir- onmental influences were common to all the traits studied, but there was also evidence for trait-specific effects. Keywords: Conduct disorder, aggression, delinquency, oppositionality, depression, twin.